Simulation is an indispensable technique to evaluate the performance of computer networks, and along with the continuous growth of network scale and diversity, the simulation systems become more enormous and complex. In this paper, we present an approach to create a distributed and Web-based 3-tier simulation architecture based on the external model access (EMA) library of OPNET. With this archite...
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Envelope domain method that is well-suited for representing large signal RF network is presented, including theory and algorithm. Subsequently, characterize a RF nonlinear system excited with a two-tone by envelope domain simulation.
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The road to 3G runs through 2G and 2.5G networks. Until 3G is deployed ubiquitously, 2-2.5G networks and endpoints dominates. The 3G subscribers should share the successful services deployed in the existing network and the service migration is needed. Redesigning and redeveloping the legacy services is a time-consuming and error-prone task. A connection view model (CVM) approach is taken to simpli...
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This paper proposes a new ranking algorithm using the hyperlink-based concept with emphases on the number of hops between Web pages. Our proposed approach takes into consideration both the importance and the relevance of a Web page associated with a query phrase. Experiments are carried out to show that the proposed approach shows great promises.
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Manually querying search engines in order to acquire a large body of related information is a tedious, error-prone process. Search engines retrieve and rank potentially relevant documents for human perusal, but do not extract facts, assess confidence, or fuse information from multiple documents. This paper present an information extraction system that aims to automate the tedious process of extrac...
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Hierarchical mobile IPv6 (HMIPv6) has long been prevailing in the realm of effective micromobility management. The HMIPv6 protocol, associated with mobile IPv6, supports route optimization to resolve 'triangle-routing' problem, and enables local route registration within a MAP domain to reduce the amount of network-wide signaling traffic. But most of the researches on micromobility related protoco...
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Automatic text classification for a Web collection is a challenge task, especially in the case that the language is not English, such as Thai. However, most of Thai educational Web pages usually include English terms due to their technical aspect. Lots of technical terms and typing errors both in Thai and in English are found in Web sites of universities. Most previous works on text categorization...
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Technology of computer and network system has changed and developed rapidly so that it requires rapid design and development especially for computer and Internet technology which play a major role in our everyday lives and business. However, Web page development and information update usually needs programming skills which can take time to collect. This paper presents framework and concept in deve...
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In this paper, a novel multiple narrow-band interferences (NBI) suppression technique based on singular value decomposition (SVD) algorithm is presented. SVD is used to approximate the interferences which then are subtracted from the received signals. The proposed technique is simple and robust. Three UWB systems are considered and simulation results show that the proposed new technique is very ef...
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Based on the Haar wavelet synthesized narrow pulse technique, the paper initially puts forward a diversity receiving and transmitting technique of Haar waveform (WD) of UWB signal. The narrow pulses synthesized by each order of Haar wavelet are sent to the receiving system through the transmitting system. The receiver uses coherent detection technique to detect each order of Haar wavelet, which ca...
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Ultra wideband (UWB) is a kind of wireless communication system which can perform high data rate with nano-second pulses of baseband, and has recently received much attention for short-range applications. Thus a high sensitivity of timing synchronization between modulation and demodulation is required. Timing synchronization error named timing jitter between transmitter and receiver has been intro...
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Considering the two limitations of UWB baseband modulation, the UWB carrier envelope modulation (CEM) scheme is presented in the paper. The UWB binary orthogonal carrier envelope modulation (BOCEM) is discussed as an example to show the realization of UWB carrier-based modulation system. The carrier frequency selection criteria is also derived. The performance analysis and simulation results show ...
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Ultra-wide bandwidth (UWB) is a prospective radio technology for wireless networks. As being approval by FCC, UWB radio has received much attention. In this paper, we propose a new multiple access protocol for time-hopping UWB ad-hoc network. As UWB system is a carrier-less impulse radio system, it is cumbersome to implement the carrier sensing capability needed in popular approaches such as carri...
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